Unit and method for managing at least one channel in an access session for accessing a service in a network

ABSTRACT

A unit ( 20 ) for managing a telecommunications network ( 1 ) includes means ( 16 ) for registering a visibility attribute associated with this channel; means ( 14 ) for receiving a request to obtain information on a channel; and means ( 14 ) for sending a response to this request taking into account the visibility attribute associated with said channel.

BACKGROUND OF THE INVENTION

The field of the invention is that of interactive services in a telecommunications network.

Although this is not limiting on the invention, the field of the invention is more particularly that of interactive multimode services.

The term “multimode” refers generally to alternating or parallel use of a plurality of modes in a combined or redundant way.

From the system point of view, an input or output mode is defined by:

-   -   a representational system;     -   a physical interaction device; or     -   a representational system and a physical interaction device in         association.

By way of non-limiting example, the invention applies to interactive services accessible in one or more of the following modes:

-   -   fixed telephone;     -   mobile telephone;     -   Internet Protocol (IP) telephone;     -   Internet access;     -   video.

A user (a physical person or a device) accesses a service during a session that is linked to that user and during which one or more channels are set up.

A session set up between two entities is controlled (set up, maintained, released, etc.) by control means distributed between those entities.

In the present document, data managed by at least part of these session control means is referred to as data “attached” to the session.

A communications channel between two entities is defined by a payload data stream (voice, video, etc.), means for controlling this stream being distributed between the two entities. The data managed by these channel control means is referred to as data “attached” to the channel.

Data attached to a first session or a first channel is said to be “visible” from a second session or from a second channel if the control means of that second session or that second channel are aware of the existence of the data. Otherwise the data is referred to as “invisible”.

Finally, if data is visible, it can be visible:

-   -   in “read” mode, if its value can only be obtained; or     -   in “read/write” mode, if its value can also be modified.

Moreover, and notably in the context of multimode services, one or more users can access the same service with a number of sessions, each including one or more channels.

For example, a user might access a server via a voice channel of a first session set up between that server and a mobile telephone of that user and simultaneously via a video channel of a second session with a computer of the same user.

At present, the deployment of multimode services remains limited because it is not possible in the current state of the art to share information between the various channels, this relative impermeability effect preventing overall service consistency.

OBJECT AND SUMMARY OF THE INVENTION

A first aspect of the invention consists of a unit for managing a channel belonging to a session for accessing a service in a telecommunications network, said management unit including:

-   -   means for registering a visibility attribute associated with         said channel;     -   means for receiving a request for obtaining information on a         channel; and     -   means for sending a response to said request taking into account         the visibility attribute associated with said channel.

Thus the management unit of the invention defines and registers a visibility attribute associated with each of the channels used to access a service.

In one particular embodiment of the invention, the visibility attributes that can be associated with a channel are as follows:

-   -   “public”, a public channel being visible to all other channels;     -   “protected”, a protected channel being visible to all the other         channels of the session of that channel; and     -   “private”, a private channel not being visible to any other         channel.

According to the invention, when the management unit receives a request to obtain information on a channel, it prepares a response taking into account the visibility attribute associated with the channel.

For example, when the management unit receives a request to obtain a list of visible channels, it responds to that request by returning a list of the references of the public channels.

If none of the channels are public channels, the management unit of the invention returns a value (NULL) representing that fact.

In one embodiment of the invention, if the request to obtain information on a first channel comes from a second channel, the response takes into account the sessions to which the first and second channels belong.

For example, the management unit of the invention returns information on a protected channel only in response to requests coming from a channel of the same session as that channel.

The invention also applies when two or more sessions provide access to the same service.

In one particular embodiment of the invention, the management unit includes:

-   -   means for registering a visibility attribute associated with a         session;     -   means for receiving a request to obtain information on a         session; and     -   means for sending a response to said request taking into account         the visibility attribute associated with the session.

One particular embodiment also provides visibility attributes of sessions.

In one particular embodiment, the visibility attribute of a session can be of two types:

-   -   “public”, a public session being visible to all sessions;     -   “private”, a private session being visible only to the channels         of that session.

In one particular embodiment of the invention, to respond to a request to obtain information on a channel, the management unit takes into account the visibility attribute of the session to which that channel belongs and a set of rules.

This set of rules defines, as it were, the prevalence between the visibility attribute associated with a session and the visibility attribute associated with a channel of that session.

This set of rules in particular resolves visibility conflicts that arise when a protected or public channel belongs to a private session.

In one particular embodiment of the invention, the management unit includes:

-   -   means for registering a visibility attribute associated with         data;     -   means for receiving a request to obtain information on data; and     -   means for sending a response to said request taking into account         the visibility attribute associated with the data.

This particular embodiment assigns a visibility attribute to the data used in the context of a service.

In one particular embodiment of the invention, the visibility attributes that can be associated with data are as follows:

-   -   “public”, public data being visible to all sessions;     -   “protected”, protected data being visible only to channels of         the same session; and     -   “private”, private data not being visible either to other         sessions or to other channels of the same session.

In one particular embodiment of the invention, the management unit further includes:

-   -   means for registering a read and/or write right associated with         data;     -   means for receiving a request to read or modify data; and     -   means for sending a response to said request taking into account         the right and the visibility attribute associated with said         data.

As mentioned above, data can be attached to a channel or directly to a session.

In one particular embodiment, when a third party sends a request to access data attached to a channel, to respond to that request the management unit of the invention takes into account the visibility attribute of that channel and a set of rules.

This set of rules in particular resolves visibility conflicts that arise when public data is attached to a protected or private channel.

In one particular embodiment of the invention, when data is attached to a session, the management unit takes into account the visibility attribute of that session and a set of rules.

This set of rules in particular resolves visibility conflicts that arise when public or protected data belongs to a private session.

In one particular embodiment, to respond to a request to obtain information on data, the management unit of the invention takes into account the session to which that data is attached and the session from which the request comes.

This embodiment therefore provides information on protected data only in response to requests coming from a channel belonging to the same session.

The invention also consists in a method of managing a channel belonging to a session for accessing a service in a telecommunications network.

This management method includes:

-   -   a step of registering a visibility attribute associated with         said channel;     -   a step of receiving a request to obtain information on a         channel; and     -   a step of sending a response to the request taking into account         the visibility attribute associated with the channel.

The advantages and particular implementations of the management method of the invention are identical to those referred to above in relation to the management device of the invention. They are not repeated here.

In one particular implementation, the various steps of the management method are determined by computer program instructions.

Consequently, the invention also consists in a computer program on an information medium, this program being adapted to be executed in a management unit or more generally in a computer and including instructions adapted to execute the steps of the above management method.

This program can use any programming language and can take the form of source code, object code or a code intermediate between source code and object code, such as a partially-compiled form, or any other desirable form.

The invention further consists in a computer-readable information medium containing instructions of the above computer program.

The information medium can be any entity or device capable of storing the program. For example, the medium can include storage means, such as a ROM, for example a CD ROM or a microelectronic circuit ROM, or magnetic storage means, for example a floppy disk or a hard disk.

Moreover, the information medium can be a transmissible medium such as an electrical or optical signal, which can be routed via an electrical or optical cable, by radio or by other means. The program of the invention can in particular be downloaded over an Internet-type network.

Alternatively, the information medium can be an integrated circuit incorporating the program, the circuit being adapted to execute the method in question or to be used in its execution.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present invention emerge from the description given below with reference to the appended drawings, which show a non-limiting embodiment of the invention. In the figures:

FIG. 1 represents, in its environment, a management unit conforming to one particular embodiment of the invention;

FIG. 2 represents, in the form of a flowchart, the main steps of a management method conforming to one particular embodiment of the invention;

FIG. 3 represents tables that define rules for resolving visibility conflicts in one particular embodiment of the invention; and

FIG. 4 is a diagram representing one example of use of the invention.

FIG. 1 represents a management unit 20 of the invention.

In the example described here, this management unit is incorporated in a server identified by the same reference number.

This management unit has the hardware architecture of a conventional computer.

It includes a processor 11, a random-access memory (RAM) 12, a read-only memory (ROM) 13, and communications means 14 for communicating with other equipment via a network 1.

The read-only memory 13 contains a computer program having instructions that execute the steps of the management method of the invention, shown in the flowchart of FIG. 2.

The management unit 20 of the invention includes a storage unit 15 that contains three tables T1, T2, and T3 of rules represented in FIG. 3.

The management unit 20 of the invention also includes a non-volatile rewritable memory 16 for storing:

-   -   visibility attributes V(S_(j)) of sessions S_(j);     -   visibility attributes V(C_(i)) of sessions C_(i);     -   visibility attributes V(D_(k)) of data D_(k); and     -   rights R(D_(k)) of the data D_(k).

In the example described here, the attributes V(S_(j)) of a session S_(j) can be of two types:

-   -   “public” (PUB), in which case the session S_(j) is visible to         other sessions that can consult the data attached to it; or     -   “private” (PRIV), in which case the session S_(j) and the data         attached to that session are not visible to other sessions.

In the example described here, the visibility attributes V(C_(i)) of a channel C_(i) can be of three types, namely:

-   -   “public” (PUB), in which case the channel C_(i) is visible to         all other sessions;     -   “protected” (PROT), in which case the channel C_(i) is visible         to channels of the same session as that channel; or     -   “private” (PRIV), in which case the channel is not visible to         other sessions or to other channels of the same session.

In the example described here, the visibility attributes V(D_(k)) of the data D_(k) can be of three types, namely:

-   -   “public” (PUB), in which case the data is visible to all other         sessions;     -   “protected” (PROT), in which case the data is visible only to         channels of the same session; or     -   “private” (PRIV), in which case the data is visible neither to         other sessions nor to other channels of the same session.

The three tables T1, T2, and T3 stored in the storage unit 15 define rules for resolving conflicts between:

-   -   the visibility attribute V(S_(j)) of a session S_(j);     -   the visibility attribute V(C_(i)) of a channel C_(i) of that         session S_(j); and     -   the visibility attribute V(D_(k)) of data D_(k) attached to the         channel C_(i) or to the session S_(j).

In the particular example described here, it is considered necessary for:

-   -   a session S_(j) to be visible so that the channels C_(i) of that         session are themselves visible; and     -   a channel C_(j) itself to be visible so that the data D_(k)         attached to that channel is visible.

Assume that a user accesses the same service on the server 20 from two terminals, namely a personal computer 11 and a mobile telephone 12, via the telecommunications network 1. To be more precise, assume that, in this example:

-   -   a first session S₁ has been set up between the computer 11 and         the server 20, this first session S₁ including a voice channel         C₁ and a visual channel C₂; and     -   a second session S₂ has been set up between the mobile telephone         12 and the server 20, this second session including only a voice         channel C₃.

Table T1 contains the rules used by the management unit 20 to resolve visibility conflicts that arise when:

-   -   data attached to a session S_(j) is accessed from the same         session S_(j); or     -   data attached to a channel C_(i) is accessed from the same         channel C_(i).

The table T2 contains rules used by the management unit 20 to resolve visibility conflicts that arise when the requirement is to access data attached to a first channel via a second channel of the same session.

The table T3 contains rules used by the management unit 20 to resolve visibility conflicts that arise when the requirement is to access data attached to a session or a channel from another session.

The following notation is used in each of these tables:

-   -   “VIS” if the data D_(k) can be rendered visible as a function of         the visibility attributes V(S_(j)), V(C_(i)) and V(D_(k)); and     -   “INVIS” if the data must remain invisible.

Table T1 indicates that in this embodiment data attached to a session is always visible from that session and that data attached to a channel is always visible from that channel.

Table T2 indicates that private data attached to a channel is invisible from all other channels of the same session and that data attached to a private channel is invisible from other channels of the same session, even if the data is public data.

Table T3 indicates that, for data to be visible from another session, the channel and the session to which that data belongs must be public.

The main steps of the management method implemented by the management unit 20 are described below with reference to FIG. 2.

In the remainder of the description, the term “object” refers interchangeably to a session, a channel or data.

From a general point of view, the management method of the invention consists of a request processing loop comprising steps E10 to E60.

The step E10 corresponds to reception of requests.

These requests can be of various types:

-   -   requests to register an object, including a visibility attribute         associated with that object; on reception of a request to         register an unregistered object, the management unit 20 stores         the visibility attribute in the non-volatile memory 16;     -   requests to dereference (unregister) an object, to eliminate an         object from the non-volatile memory 16;     -   requests to obtain a list of public object references;     -   requests to modify the visibility attribute of an object, these         requests being processed by the management unit 20 only if they         come from the session to which that object belongs;     -   requests to modify the information associated with a public         object;     -   requests to obtain information on a public object.

If the request received in the step E10 is a registration or dereferencing request, the step E10 is followed by a step E20 during which the management unit 20 registers or eliminates the reference of an object and the visibility attributes of that object in the non-volatile memory 16.

This registration or dereferencing step E20 is followed by a step E30 during which the management unit 20 sends a response to the request received in the step E10, this response containing either the reference of the object or a NULL value if an error has occurred.

An error can in particular occur if a registration or dereferencing request in respect of a channel is received from a session other than that to which that channel belongs.

This step E30 of sending a response is followed by the step E10 of receiving the next request.

When the management unit 20 of the invention receives a request for obtaining or modifying information on an object, the request reception step E10 is followed by a step E40 of obtaining at least one visibility criterion.

If the request relates to a session S_(j), the visibility attribute V(S_(j)) of that session is obtained from the non-volatile memory 16 during this step.

If this request relates to a channel C_(i), the visibility attribute V(C_(i)) of that channel and the visibility attribute of the session to which that channel belongs are obtained from the non-volatile memory 16.

If the request relates to data D_(k), the visibility attribute V(D_(k)) of that data, where applicable the visibility attribute V(C_(i)) of the channel to which that data is attached, and where applicable the visibility attribute V(S_(j)) of the session to which that data is attached are obtained from the non-volatile memory 16.

The step E40 of obtaining visibility criteria is followed by a step E50 of managing visibility conflicts.

In the example described here, if this request relates to data, this conflict management step consists in obtaining the value “VIS” or “INVIS” from the tables T1 to T3.

If the management unit 20 obtains the value “INVIS”, the constant NULL is returned in response to the request to represent the fact that the data is invisible and that the information requested is not accessible.

In contrast, if the value “VIS” is obtained, i.e. if the requested data D_(k) is visible, the response to the request depends on the rights R(D_(k)) associated with that data.

To be more precise, if these rights are reading rights, the data D_(k) can only be read.

If these rights are writing rights, the data D_(k) can also be modified.

A scenario conforming to the invention for managing the channels C₁, C₂, C₃ set up by the computer 11 and the mobile telephone 12 to access the server 20 from FIG. 1 is described below with reference to FIG. 4.

During a step e1, the voice mode of the computer 11 requests referencing of the session S₁ by sending a referencing request.

This referencing request is received during the step E10. As the management unit 20 is unaware of the session S₁, a reference RefS₁ is created (step E20) and returned (step E30) to the personal computer 11 in the channel C₁.

During a step e2, the visual mode of the computer 11 requests referencing of the session S₁. As the session is stored in the volatile memory 16, the reference RefS₁ of this session is returned to the computer 11 via the channel C₂.

During a step e3, the voice mode of the computer 11 requests referencing of the channel C₁ in the management unit 20.

The reference RefC₁ is created (step E20) and returned to the personal computer 11 via the channel C₁.

During a step e4, the voice mode of the computer 11 requests referencing of the visual channel C₂. The reference RefC₂ is created and sent to the computer 11 via the channel C₂.

During a step e5, the voice mode of the computer 11 stores data A (session level data attached to the session S₁).

During a step e6, the visual mode of the computer 11 registers data B attached to the visual channel C₂.

During a step e7, the voice mode of the computer 11 obtains a list of the visible channels of the session S₁ from the management unit 20.

During a step e8, the voice mode of the computer 11 accesses the data B attached to the channel C₂, if the voice mode of the computer 11 has the right to read that data.

During a step e9, the voice mode of the mobile telephone 12 requests referencing of the session S₂. As S₂ is not referenced in the management unit 20, a reference RefS₂ is created and returned to the mobile telephone 12 via the channel C₃.

During a step e10, the voice mode of the computer 11 requests referencing of the channel C₃. The reference RefC₃ is created and returned to the voice mode of the mobile telephone 12 via the channel C₃.

During a step e11, the voice mode of the mobile terminal 12 obtains a list of visible sessions from the management unit 20.

During a step e12, the voice mode of the mobile terminal 12 accesses the data A of the session S₁ if this voice mode has the right to read that data.

During a step e13, the voice mode of the mobile terminal 12 recovers the list of the visible channels of the session S₁ from the management unit 20.

During a step e14, the voice mode of the mobile terminal 12 accesses the data B attached to the channel C₂ if this voice mode has the right to read that data.

During a step e15, the voice mode of the mobile terminal 12 requests dereferencing of the channel C₃.

The reference RefC₃ is eliminated from the non-volatile memory 16.

During a step e16, the voice mode of the mobile terminal 12 requests dereferencing of the session S₂.

The reference RefS₂ is eliminated from the non-volatile memory 16.

During a step e17, the visual mode of the computer 11 requests dereferencing of the channel C₂.

The reference RefC₂ is eliminated.

During a step e18, the visual mode of the computer 11 requests dereferencing of the session S₁.

As the reference RefS₁ is also used by the voice mode of the computer 11, it is not eliminated from the non-volatile memory 16.

During a step e19, the voice mode of the computer 11 requests dereferencing of the voice channel C₁.

The reference RefC₁ is eliminated.

During a step e20, the voice mode of the computer 11 requests dereferencing of the session S₁.

As the reference RefS₁ is no longer used by any mode, it is eliminated from the session register.

In the embodiment described here, the management method of the FIG. 2 flowchart is applied to a set of functions specified below.

The instructions of each of these functions are stored in the non-volatile ROM 13 of the unit 20 of the invention.

A) Session Level Functions

1) Registering a Session

The “registerSession” function registers a session. It includes the following parameters:

Parameter Type Comment idUser Obligatory Session identifier parameter Visibility Obligatory Session visibility parameter Possible values: PUB: session is visible to all other sessions; PRIV: session is visible only to channels of the same session Return If the session is new, the return value value is the reference of the registered new session If the session exists already (i.e. if the idUser parameter is the same) the return value is the reference of the existing session If an error occurs, the return value is “NULL”

2) Obtaining a List of Visible Sessions

The “getListSession” function obtains a list of references of sessions registered with “public” visibility.

Parameter Type Comment Return List of references of sessions value having “PUB” type visibility If an error occurs, the return value is “NULL”

3) Updating the Visibility of a Session

The “setSessionScope” function updates the visibility of a session. Only a session can modify its visibility.

Parameter Type Comment refSession Obligatory Session reference parameter Visibility Obligatory Session visibility parameter Possible values: PUB: session is visible to all other sessions; PRIV: session is visible only to channels of the same session Return Session reference or value “NULL” if an error occurs (for example sent by another session)

4) Modifying Information on a Session

The “setSessionInfo” function modifies the information on a session with visibility of “PUB” type.

Parameter Type Comment refSession Obligatory Session reference parameter refInfo Obligatory Reference of the information of parameter the session Return Reference of the information of value the session If an error occurs, the return value is “NULL”

5) Obtaining Information on a Session

The “getSessionInfo” obtains information on a session with visibility of type “PUB”.

Parameter Type Comment refSession Obligatory Session reference parameter Return Reference of the information of value the session (containing its visibility, number of visible channels, etc.) If an error occurs, the return value is “NULL”

6) Dereferencing a Session

The “unregisterSession” function dereferences a session.

Parameter Type Comment refSession Obligatory Session reference parameter Return If the session has no more value channels attached, the return value is the reference of the session that has just been eliminated Otherwise, the return value is “NULL”

B) “Channel” Level Functions

1) Registering a Channel

The “registerChannel” function registers a referenced channel.

Parameter Type Comment refSession Obligatory Reference of session to which parameter channel belongs Visibility Obligatory Channel visibility parameter Possible values: PUB: channel is visible to all other channels, regardless of session PROT: channel is visible to all other channels of the session PRIV: channel is not visible to any other channel If a channel belongs to a private session, it is not visible from other sessions regardless of the rights attached to the channel In other words, session level rights take precedence over channel level rights idChannel Obligatory Channel identifier parameter The format of this information is unrestricted For example it can take the values 1, 2, 3, . . . or Web, Voice, TV, . . . Return Reference of the registered new value channel or “NULL” if an error occurs (rights or creation problem)

2) Obtaining a List of Visible Channels

The “getListChannel” function obtains a list of the references of channels registered with a visibility of “PUB” type.

Parameter Type Comment refChannel Obligatory Session reference parameter Return Lisr of references of channels value having visibility of “PUB” type or “NULL” if an error occurs

3) Modifying the Visibility of a Channel

The “setChannelScope” function updates the visibility of a channel.

Parameter Type Comment refChannel Obligatory Channel reference parameter Visibility Obligatory Channel visibility parameter Possible values: PUB: channel is visible to all other channels, regardless of session PROT: channel is visible to all other channels of the session PRIV: channel is not visible to any other channel of the same session Return Channel reference or value “NULL” if an error occurs (rights or visibility problem)

4) Modifying Information on a Session

The “setChannelInfo” function modifies information associated with a channel with visibility of “PUB” type.

Parameter Type Comment refChannel Obligatory Channel reference parameter refInfo Obligatory Reference of the information of parameter the channel Return Reference of the information of value the channel or “NULL” if an error occurs

5) Obtaining Information on a Channel

The “getChannelInfo” function obtains information on a channel of a session.

Parameter Type Comment refChannel Obligatory Channel reference parameter Return Reference of the information of value the channel (containing scope, type of channel, etc.) or “NULL” if an error occurs

6) Dereferencing a Channel

The “unregisterChannel” function dereferences a channel of a session.

Parameter Type Comment refChannel Obligatory Channel reference parameter Return Reference of channel that has just value been eliminated or “NULL” if an error occurs

C) “Data” Level Functions

1) Registering Data a) Registering Session Level Data

The “registerSessionData” function registers session level data.

Parameter Type Comment refSession Obligatory Session reference parameter Visibility Obligatory Visibility of data: parameter PUB: data is visible to all PROT: data is visible only to channels of the same session PRIV: data is not visible to other sessions or to other channels of the same session If session level data belongs to a private or protected session, it is not visible from other sessions regardless of the rights attached to the data In other words session level takes precedence over data level Rights Obligatory Rights to manipulate data parameter Possible values: RW: data is accessible in read mode and in write mode R: data is accessible only in read mode W: data is accessible only in write mode idData Obligatory Data identifier parameter The format of this information is unrestricted (character string) Return Reference of the registered data value or “NULL” if an error occurs (compatibility of visibility or rights or creation problem)

b) Registering Channel Level Data

The “registerChannelData” function registers channel level data (for a given session).

Parameter Type Comment refChannel Obligatory Channel reference parameter Visibility Obligatory Visibility of data: parameter PUB: data is visible to all PROT: data is visible only to channels of the same session PRIV: data is not visible to other sessions or to other channels of the same session If channel level data belongs to a private or protected session, it is not visible from other sessions regardless of the rights attached to the data In other words, session level takes precedence over data level Rights Obligatory Rights to manipulate data parameter Possible values: RW: data is accessible in read mode and in write mode R: data is accessible only in read mode W: data is accessible only in write mode idData Obligatory Data identifier parameter The format of this information is unrestricted (character string) Return Reference of registered data or value “NULL” if an error occurs (compatibility of visibility or rights or creation problem)

2) Modifying the Visibility of Data

The “setDataScope” function modifies the visibility of data.

Parameter Type Comment refData Obligatory Data reference parameter Visibility Obligatory Visibility of data: parameter PUB: data is visible to all PROT: data is visible only to channels of the same session PRIV: data is not visible to other sessions or to other channels of the same session To modify the visibility of data, a channel must have rights to write the data Return Data reference or value “NULL” if an error occurs (compatibility of visibility or rights problem) 3) Modifying Rights Associated with Data

The “setDataRights” function modifies the rights associated with data.

Parameter Type Comment refData Obligatory Data reference parameter Rights Obligatory Rights to manipulate data parameter Possible values: RW: data is accessible in read mode and in write mode R: data is accessible only in read mode W: data is accessible only in write mode Return Data reference or value “NULL” if an error occurs (compatibility of visibility or rights problem)

4) Modifying the Value of Data

The “setData” function modifies the value of data.

Parameter Type Comment refData Obligatory Data reference parameter data Obligatory Reference of the value of the data parameter Return Data reference or value “NULL” if an error occurs (compatibility of visibility or rights or creation problem)

5) Obtaining Information on Data

The “getDataInfo” function obtains information on data. The data must be associated with a visibility of “PUB” type.

Parameter Type Comment refData Obligatory Data reference parameter Return Reference of information on data value (containing proprietor, visibility and access rights, etc.) or “NULL” if an error occurs (compatibility of visibility or rights problem)

6) Obtaining the Value of Data

The “getData” function obtains the value of data.

Parameter Type Comment refData Obligatory Data reference parameter Return Reference of the value of the data value or “NULL” if an error occurs (compatibility of visibility or rights problem)

7) Obtaining a List of Visible Data a) Obtaining a List of Session Level Visible Data

The “getListSessionData” function obtains a list of the references of the visible data registered for a session. The visibility of the session to which the data belongs must be of “PUB” type.

Parameter Type Comment refSession Obligatory Session reference parameter Return List of references of visible data value or “NULL” in the event of an error (compatibility of visibility or rights problem)

b) Obtaining a List of Channel Level Visible Data

The “getListChannelData” function obtains a list of the references of the visible data registered for a channel. The visibility of the session to which this data belongs must be of “PUB” or “PROT” type.

Parameter Type Comment refChannel Obligatory Channel reference parameter Return List of references of visible data value or “NULL” in the event of an error (compatibility of visibility or rights problem)

8) Dereferencing Data

The “unregisterData” function dereferences data.

Parameter Type Comment refData Obligatory Data reference parameter Return Reference of data that has just value been eliminated or “NULL” in the event of an error (compatibility of visibility or rights problem) 

1. A management unit (20) for managing a channel (C_(i)) belonging to a session (S_(j)) for accessing a service in a telecommunications network (1), said management unit (20) including: means (16) for registering a visibility attribute (V(C_(i))) associated with said channel (C_(i)); means (14) for receiving a request (getChannelInfo) for obtaining information on one of said channels (C_(i)); and means (14) for sending a response to said request (getChannelInfo) taking into account the visibility attribute (V(C_(i))) associated with said channel (C_(i)).
 2. The management unit (20) according to claim 1, wherein said request (getChannelInfo)to obtain information on a first channel (C_(i)) comes from a second channel (C_(i)), wherein said response takes into account the session to which said first channel (C_(i)) belongs and the session (S_(j)) to which said second channel (C_(i)) belongs.
 3. The management unit (20) according to claim 1, wherein at least two sessions (S_(j), S_(j)) enable access to said service, wherein said management unit further comprises: means (16) for registering a visibility attribute (V(S_(j))) associated with one of said sessions (S_(j)); means (14) for receiving a request (getSessionInfo) to obtain information on a session (S_(j)); and means (14) for sending a response to said request taking into account the visibility attribute (V(S_(j))) associated with said session (S_(j)).
 4. The management unit (20) according to claim 3, wherein the response to said request (getChannelInfo) to obtain information on a channel (C_(i)) takes into account the visibility attribute (V(S_(j))) associated with the session (S_(j)) to which said channel (C_(i)) belongs and a set of rules (15).
 5. The management unit (20) according to claim 1, comprising: means (16) for registering a visibility attribute (V(D_(k))) associated with data (D_(k)); means (14) for receiving a request (getDataInfo) to obtain information on said data (D_(k)); and means (14) for sending a response to said request taking into account the visibility attribute (V(D_(k))) associated with said data (D_(k)).
 6. The management unit (20) according to claim 5, comprising: means (16) for registering a read and/or write right (R(D_(k))) associated with said data (D_(k)); means (14) for receiving a request (setData) to read or modify said data (D_(k)); and means (14) for sending a response to said request taking into account the right (R(Dk)) and the visibility attribute (V(D_(k))) associated with said data (D_(k)).
 7. The management unit (20) according to claim 5, wherein said data (D_(k)) is attached to a channel (C_(i)), and wherein the response to said request (getDataInfo) to obtain information on said data (D_(k)) takes into account the visibility attribute (V(S_(j))) associated with said channel (C_(i)) and a set of rules (15).
 8. The management unit (20) according to claim 5, wherein said data (D_(k)) is attached to a session (S_(j)), and wherein the response to said request (getDataInfo) to obtain information on said data (D_(k)) takes into account the visibility attribute (V(S_(j))) associated with said session (S_(j)) and a set of rules (15).
 9. The management unit (20) according to claim 7, wherein the response to said request (getDataInfo) to obtain information on said data (D_(k)) takes into account the session (S_(j)) to which said data is attached and the session from which the request (getDataInfo) comes.
 10. A method of managing a channel (C_(i)) belonging to a session (S_(j)) for accessing a service in a telecommunications network, said management method including: a step (E20) of registering a visibility attribute (V(C_(i))) associated with said channel (C_(i)); a step (E10) of receiving a first request (getChannelInfo) to obtain information (I(C_(i))) on said channel (C_(i)); and a step (E60) of sending a response to said first request (getChannelInfo) taking into account the visibility attribute (V(C_(i))) associated with said channel (C_(i)).
 11. A computer program including instructions for executing the steps of the management method according to claim 10 when said program is executed by a computer.
 12. A storage medium (13) readable by a computer (20) storing a computer program comprising instructions for executing the steps of the management method according to claim
 10. 